Unless somebody's got "before" and "after" pictures, it's probably their word against your word. Did you have them do any kind of a check sheet at the beginning stating any items that needed repair or accepting that the home was in good condition and no repair items were noted?
I would definitely take some photos at this point, so you can at least prove the condition it's in now.
I personally don't deal in property management, but maybe somebody familiar with the general rental laws and especially the laws in your state would be helpful. Let's hope you get some useful advice. Sorry that you've got a trashed home now.